/Engine/Source/Runtime/UMG/Public/Slate/WidgetRenderer.h
bool DrawInvalidationRoot ( [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [SVirtualWindow](API\Runtime\Slate\Widgets\SVirtualWindow) > & VirtualWindow, [UTextureRenderTarget2D](API\Runtime\Engine\Engine\UTextureRenderTarget2D) * RenderTarget, [FSlateInvalidationRoot](API\Runtime\SlateCore\FastUpdate\FSlateInvalidationRoot) & Root, const [FSlateInvalidationContext](API\Runtime\SlateCore\FastUpdate\FSlateInvalidationContext) & Context, bool bDeferRenderTargetUpdate )